1. Field of the Invention
The present invention relates to an image display apparatus comprising a flat displaying apparatus with a number of (for example fifteen) line cathodes.
More particularly, the present invention concerns an image display apparatus for displaying image by means of a phosphor screen and a plural number of parallel disposed line cathodes wherein deflections of electron beams are controlled by means of digitally processed deflection signals.
2. Description of the Prior Art
Hitherto, for an image display apparatus for a television set, a cathode-ray tube having a single electron gun or, three electron guns set in a neck part of a bulky cone shaped vacuum enclosure has been used for long time. The shortcoming of the conventional cathode ray tube is a large depth in comparison with the size of the screen face, disabling to provide a flat and compact television set. Though EL display apparatus, plasma display apparatus or liquid crystal display apparatus has been developed, these are not sufficiently usable for practical use because they have problems in brightness, contrast or color displaying.
As a novel flat type image display apparatus using electron beams, the applicant proposed an invention in a senior Japanese Patent Application Sho 56-20618 (published in the Japenese un-examined Patent Application Sho 57-135590 which was published only after the priority date of the present case). The art of the senior application is a color display apparatus comprising:
a color phosphor screen comprising a first predetermined number of horizontally divided sections each comprising a set of regions of primary color phosphors,
an electron beam source for in-turn emitting a second predetermined number of horizontal rows of electron beams, each row having the first predetermined number of electron beams, producing one horizontal line on the color screen,
a horizontal deflection means for selective impingements of the electron beams on the regions in turn selected corresponding kinds of primary color phosphors at one time, in turn changing colors of the horizontally divided sections,
a vertical deflection means for vertically deflecting the electron beams in such a manner that electron beams of a horizontal row impinges the phosphor screen in one vertically divided segment which is corresponding to the one horizontal row, thereby vertically moving the one horizontal line in the vertically divided segment,
an electron beam control means for simultaneous controlling of intensities of respective electron beams responding to color video signal for the selected kind of primary color to produce a line-at-a-time displaying of color video picture, and
a flat shaped vacuum enclosure containing the above-mentioned components therein, one end face thereof forming a screen face in which the color phosphor screen is provided.